This application is for the continued support of a training program in Allergy and Clinical Immunology that is designed for postdoctoral medical and pediatric trainees. There is a double training faculty. Firstly, clinician-researchers from Pediatrics, the Department of Medicine in Allergy and Clinical Immunology, Rheumatology, Pulmonary, Gastroenterology, Dermatology, Infectious Diseases and Human Translational Immunology. Secondly, Mentors, who are basic scientists mainly from Yale's outstanding Department of Immunobiology faculty. Together, their expertise spans nearly all of the areas important to allergy, clinical immunology, and modern immunology;including: humoral, cellular, molecular, genetic, biochemical, antigen- processing/presenting, and signaling research. Some faculty are experts in Lyme disease, which was discovered at Yale by faculty in this training program. We continue with siRNA treatment of ticks to understand pathogenesis and develop vaccines. There is rigorous training in Allergy, and Clinical immunology, and some in Immunologic aspects of Rheumatology, Dermatology, Gastroenterology, Pulmonary, and ENT. The training faculty is well equipped with major instruments including: outstanding flow cytometry, oligonucleotide synthesizer, protein sequinator and access to array and deep cDNA sequencing (Illumina/Solexa). This is a small high quality training program, taking only one new fellow per year, with a large faculty emphasizing the need for at least of 3-5 years of laboratory research to prepare trainees for positions in research medicine, upon which we are focused. The faculty have a strong training record and collaborative research interactions. The fellows spend their first year in clinical activities. The second and third years entirely in a research project under an Immunobiology faculty mentor, while taking various immunobiology and clinical science courses, participating in weekly seminars and journal clubs, and regularly giving talks on their research, and immunologic/allergy subjects of interest. In summary, the program offers unique and very high quality training of outstanding candidates for future positions in academic medicine and pediatrics, and has been quite successful in this regard over more than 30 years of continuous funding. PUBLIC HEALTH RELEVANCE: This is a renewal application for a T32 Allergy and Clinical Immunology (A and I) Training Grant (AI-07174) of more than 30 years duration that supports only one fellow a year for three years. The program has an excellent training record. Note that 5 recent graduates have gone on to academic positions. Besides completely covering core allergy and immunodeficiency, the program is distinguished by a long focus on the T cell aspect of allergy;effector T cells and regulatory T cells, and a basic science Immunobiology research experience Currently, this is manifested by the current fellows doing their research with a member (Eric Meffre) of our most outstanding Immunobiology Department headed by Richard Flavell. This research is on molecular analysis of human B cells from immunodeficient patients and on the B cells of atopic allergic patients. We are in the final stages of recruiting new leadership (Talal Chatila of UCLA);There are other competing candidates if this should not come to fruition. With a new chief, we then plan to create a fully combined and fused adult and pediatric A and I section, and in addition this combined section will secondarily join our Human Translational Immunology (HTI) division of the basic science Immunobiology Department. This will result in formal and informal interactions of our fellows with researchers working on human immunologic diseases (autoimmunity, transplantation and cancer) with our joined Allergy and Immunology as a central element. In summary, This is a renewal application for a highly successful Allergy and Immunology T32 program with a high track record of placing graduates in academic positions, and a focus beyond conventional allergy, on relevant T cells. Further, focus is basic science immunology research with our outstanding Immunobiology Department, and newly planned fusion of Pediatric and Adult Allergy and Immunology into one section, also secondarily joining our emerging Human Translational Immunology division of Immunobiology. Together these aspects offer our trainees an exceptional program;that probably results in our very high incidence of their placement in academic departments.